Wendy Searle in training near her home in Salisbury for her solo expedition to the south pole.
Photograph: Adrian Sherratt for the Observer

When Louis Rudd crossed the finishing line of his 925-mile solo trek across Antarctica last month, the first person he contacted was Wendy Searle. “I’ve done it!!!!” the army captain texted her.

It was the news that the 41-year-old Searle, a Ministry of Defence civil servant and Rudd’s expedition leader, had spent sleepless nights waiting for. “I’d known he was going to do it two or three days before but hearing he was there safely, that he had completed it as he’d set out to … I was elated. And completely relieved.”

Searle will need to ski 702 miles across the frozen continent in less than 38 days, 23 hours and five minutes. “I can’t have any outside assistance and I have to take everything with me in a special sledge called a pulk: all my food, my fuel, my supplies, everything. I can’t have any food resupplies or medical help. I cannot even accept a cup of tea,” she said. “I’ll be completely alone and, in all likelihood I won’t see anybody else.”

Searle is 5ft 5in tall and weighs just over 60kg; the pulk will weigh over 80kg. As training for the expedition, she is spending more than 10 hours a week lifting weights and running up and down hills pulling a tyre, while also holding down a full-time job in the Ministry of Defence press office.

Knowing how difficult and dangerous the trip is going to be forces Searle to prioritise it. “When you know that, if you don’t do your training, one day that might be the difference between success and failure, then it’s a huge motivator.”

Her family – her husband is a soldier and they have three teenage daughters and a nine-year-old son – are doing all they can to support her. “My children are super-independent, and they do a lot of managing upwards. They’ll say, ‘don’t forget parents evening and these are the appointments I’ve got you’. They’re amazing.” She is determined to show them that following your dreams is worth doing. “I want my children to think: if you pursue things with a passion, you will achieve the results you want to. I want them to see that it’s OK to pursue something with a white-hot passion in a single-minded way and focus on a goal.”

Five years ago, Searle had never considered crossing the Antarctic. Then she managed the media campaign of an expedition to the south pole by a team of military personnel. “I became hooked.”

She discovered the first woman hadn’t set foot on Antarctica until 1935, even though men had been going there for 100 years before that. It made her wonder if she could have a go herself. “Being around the pole community made it seem like a totally normal idea.”

Despite the fact that she’d had no previous polar training and had never skied before, she successfully skied 350 miles across the Greenland ice sheet last year. “One thing I learned is that my polar expedition is going to be incredibly tough, mentally. I definitely missed my children. But all I could think at the time was: no one day has been as bad or is ever going to be as bad as the six months I spent pretty much on my own in Germany when I was 25. My husband was away fighting in Iraq, I had a house, a dog and three children under four I was solely responsible for, and six months of just absolutely relentless grinding tiredness.”

As a woman, she faces certain physical challenges. “If you’re going for a pee in the Antarctic it is decidedly easier from a logistics point of view to be a guy. Periods are also a massive issue.” She will take medication to stop herself menstruating.

Training for her adventures has changed who she is as a person. “Doing things that push me beyond what I thought I might be able to do, that has become a huge part of my life. I can’t imagine not doing those things now.” Searle is still raising money to fund the £50,000 expedition and hopes to raise a further £50,000 for charity. She says it is more difficult to attract sponsorship as a female polar explorer. “People need to get behind female adventurers. I asked a well-known TV agent why she doesn’t have more of us on her books and she said: ‘Honestly, there just isn’t the market for it.’ I’ve heard people in bookshops looking for adventure titles say: ‘Oh no, I don’t want to read anything by a woman.’”

This kind of sexism is a vicious circle, she says. “If you’re not seeing women and mothers going on expeditions and doing amazing things, then how do you know women do that?” But they do, she says – she is part of a community of would-be female adventurers joining groups such as Adventure Queens or Love Her Wild.

Searle hopes her story will change perceptions about who should be doing polar travel and is dismayed by the number of women she meets who tell her they could never do what she is doing. “They say that without even stopping to think about whether they could. I’ve got four kids and a full-time job. If I can do it, why can’t they?”

But she adds: “I think there’s definitely a groundswell of women who want to go out and have adventures. They’re doing cool stuff, they just don’t shout about it. They don’t need that validation.”